function addToolbox () {
    return `
<category name="%{BKY_SINGLELED_CATEGORY}" id="SINGLELED_CATEGORY" colour="#FF5511" secondaryColour="#FF5511">
    <block type="singleLED_setLEDState" id="singleLED_setLEDState">
    <field name="pin">GPIO1</field>
    <shadow type="math_number">
        <field name="state">high</field>
    </shadow>
    </block>
</category>`;
}
// test "function can work??"
//         <field name="pin">GPIO1</ame="state">

exports = addToolbox;
/**
<block type="arduino_pin_setPinMode">
    <field name="PIN">0</field>
    <field name="MODE">INPUT</field>
    </block>

<block type="arduino_pin_setDigitalOutput">
    <field name="PIN">0</field>  // drop
    <value name="LEVEL">     // value is 
        <shadow type="arduino_pin_menu_level">
            <field name="level">HIGH</field>
        </shadow>
    </value>
</block>

<block type="arduino_pin_setPwmOutput">
    <field name="PIN">3</field>
    <value name="OUT">
        <shadow type="math_uint8_number">
            <field name="NUM">255</field> // value means can use Valuetocode?
        </shadow>
    </value>
</block>
*/

/*
<category name="%{BKY_SINGLELED_CATEGORY}" id="SINGLELED_CATEGORY" colour="#FF0000" secondaryColour="#FF0000">
    <block type="singleLED_setLEDState" id="singleLED_setLEDState">
        <value name="pin">
            <shadow type="math_number">
                <field name="NUM">2</field>
            </shadow>
        </value>
    </block>
</category>`;

*/